The present application relates to an abnormality determination device for a variable geometry turbocharger having a nozzle mechanism capable of changing a flow path area of exhaust gas with an actuator. The abnormality determination device includes: a first detection part configured to be capable of detecting at least one of a load of the actuator or supply energy to the actuator; and a determination part configured to determine that an abnormality is present, if a detection result by the first detection part is out of an allowable range corresponding to an operational state of the variable geometry turbocharger.